1. Field of the Invention
The present invention relates to the exploration of underwater environments by use of submersed sensors arrayed in a manner such that passive sensors receive signals generated by active electromagnetic or sonar transducers. The signals are reflected back to the sensors in such a way that 360.degree. coverage of the reflective signals can be processed aboard a vessel deploying the array in order to provide continuous monitoring and analysis of these returned or received signals.
2. Description of the Prior Art
Sea going vessels and aircraft have employed arrays of sensors that are deployed in the water and towed at moderate speeds to sense environmental conditions including, for example, the progress of underwater salvage operations, oil explorations systems, and in fish finding and bottom contour plotting systems. Generally, these towed arrays comprise horizontal streamers that are often equipped only to sense acoustic energy and often cannot be deployed at relatively low vessel speeds due to the likelihood of the sensing array becoming fouled in the towing ships propeller or screw. A further disadvantage of such prior art towed arrays is that they do not lend themselves to effective operation in relatively shallow water.
Hueter, U.S. Pat. No. 3,141,148, shows a vertically oriented array of hydrophones arranged on vertically spaced "decks" suspended on a central support structure. Carter, U.S. Pat. No. 4,486,869, shows a vertically oriented array of hydrophones arranged on a support structure that includes rigid circumaxially spaced rods rather than cables that can be reeled up to allow faster deployment of the system. Uchihashi et al., U.S. Pat. No. 4,866,682, like Carter '869, show a rigid structure rather than a readily deployable array of sensors such as disclosed herein.